Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

backlight: led-bl: Add devlink to supplier LEDs

LED Backlight is a consumer of one or multiple LED class devices, but devlink is currently unable to create correct supplier-producer links when the supplier is a class device. It creates instead a link where the supplier is the parent of the expected device.

One consequence is that removal order is not correctly enforced.

Issues happen for example with the following sections in a device tree overlay:

// An LED driver chip pca9632@62 { compatible = "nxp,pca9632"; reg = <0x62>;

// ...

addon_led_pwm: led-pwm@3 { reg = <3>; label = "addon:led:pwm"; }; };

backlight-addon { compatible = "led-backlight"; leds = <&addon_led_pwm>; brightness-levels = <255>; default-brightness-level = <255>; };

In this example, the devlink should be created between the backlight-addon (consumer) and the pca9632@62 (supplier). Instead it is created between the backlight-addon (consumer) and the parent of the pca9632@62, which is typically the I2C bus adapter.

On removal of the above overlay, the LED driver can be removed before the backlight device, resulting in:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... Call trace: led_put+0xe0/0x140 devm_led_release+0x6c/0x98

Another way to reproduce the bug without…

In the Linux kernel, the following vulnerability has been resolved:

backlight: led-bl: Add devlink to supplier LEDs

LED Backlight is a consumer of one or multiple LED class devices, but devlink is currently unable to create correct supplier-producer links when the supplier is a class device. It creates instead a link where the supplier is the parent of the expected device.

One consequence is that removal order is not correctly enforced.

Issues happen for example with the following sections in a device tree overlay:

// An LED driver chip pca9632@62 { compatible = "nxp,pca9632"; reg = <0x62>;

// ...

addon_led_pwm: led-pwm@3 { reg = <3>; label = "addon:led:pwm"; }; };

backlight-addon { compatible = "led-backlight"; leds = <&addon_led_pwm>; brightness-levels = <255>; default-brightness-level = <255>; };

In this example, the devlink should be created between the backlight-addon (consumer) and the pca9632@62 (supplier). Instead it is created between the backlight-addon (consumer) and the parent of the pca9632@62, which is typically the I2C bus adapter.

On removal of the above overlay, the LED driver can be removed before the backlight device, resulting in:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... Call trace: led_put+0xe0/0x140 devm_led_release+0x6c/0x98

Another way to reproduce the bug without…

kernel-devel-6.18.5-1.1 on GA media

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 178 more

In the Linux kernel, the following vulnerability has been resolved: backlight: led-bl: Add devlink to supplier LEDs LED Backlight is a consumer of one or multiple LED class devices, but devlink is currently unable to create correct supplier-producer links when the supplier is a class device. It creates instead a link where the supplier is the parent of the expected device. One consequence is that removal order is not correctly enforced. Issues happen for example with the following sections in a device tree overlay: // An LED driver chip pca9632@62 { compatible = "nxp,pca9632"; reg = <0x62>; // ... addon_led_pwm: led-pwm@3 { reg = <3>; label = "addon:led:pwm"; }; }; backlight-addon { compatible = "led-backlight"; leds = <&addon_led_pwm>; brightness-levels = <255>; default-brightness-level = <255>; }; In this example, the devlink should be created between the backlight-addon (consumer) and the pca9632@62 (supplier). Instead it is created between the backlight-addon (consumer) and the parent of the pca9632@62, which is typically the I2C bus adapter. On removal of the above overlay, the LED driver can be removed before the backlight device, resulting in: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 ... Call trace: led_put+0xe0/0x140 devm_led_release+0x6c/0x98 Another way to reproduce the bug without any device…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder um nicht spezifizierte Auswirkungen zu erzielen.